Textile sizing composition



United States Patent 3,427,192 TEXTILE SIZING COMPOSITION Edgar Dare Bolinger, Spartanburg, S.C., assignor to Deering Millikan Research Corporation, Spartanburg, S.C., a corporation of Delaware No Drawing. Filed May 20, 1964, Ser. No. 368,993 US. Cl. 117--139.5 17 Claims Int. Cl. D06n1 13/00, 15/00 ABSTRACT OF THE DISCLOSURE An aqueous textile sizing composition consisting essentially of a yarn lubricant, a styrene-maleic acid copolymer and a water soluble polyurethane which is the reaction product of a diisocyanate and a polyalkylene glycol. The ratio of the copolymer to the polyurethane is from about 9:1 to 1:9 by weight. The process includes sizing polyester warp yarns by either a one dip or two-dip coating procedure.

This invention relates to a process for sizing warp yarns and to sizing compositions employed therein.

Difliculties in sizing certain synthetic fibers and blends of natural and synthetic fibers such as for instance polyester fibers and polyester-cotton fiber blends has resulted in the production of a high percentage of seconds primarily due to high warp breakage.

Water-soluble polyurethanes are acceptable sizes for synthetic fiber yarns such as polyester yarns when employed under controlled low humidity conditions but have too great a moisture sensitivity for high or uncontrolled humidity conditions. That is to say, the high relative humidities which are present in most textile weave rooms, i.e., 65 to 80% cause difiiculties with polyurethane sizing compositions. The moisture sensitivity of the polyurethane sizes has been greatly reduced by the blending of styrene-maleic anhydride copolymers with the watersoluble polyurethanes. The blending of the anhydride copolymers, however, reduced the lubricating properties of the water-soluble polyurethane and caused the size to abrade off and powder at the reed and heddles and to form a build-up on the shuttle of weaving equipment.

Conventional size formulations employ lubricants to prevent size from abrading ofi. Conventional sizes and lubricants are incompatible, however, and necessitate the use of wetting agents such as sulfonated oils in order to achieve a proper blending. The wetting agent usually has the effect of weakening the film strength of the size.

It is therefore an object of this invention to provide a process for sizing both filament and spun polyester fibers and blends of polyester fibers.

It is another object of this invention to provide a sizing composition which has good lubricating properties and which contains as a basic component a water-soluble polyurethane.

It is still another object of this invention to provide a sizing composition which has low moisture affinity and good lubricating properties and which contains as a basic component a water-soluble polyurethane.

In accordance with this invention, it has now been discovered that a size employing water-soluble polyurethanes wherein the moisture aflinity has been reduced may be satisfactorily employed by applying a yarn lubricant to the yarn either subsequent to sizing with the water-soluble polyurethane or simultaneously by incorporation of the lubricant in the polyurethane sizing composition. While any yarn lubricant which is dispersible in a water-soluble polyurethane size may be employed, such as oil lubricants, higher fatty acid lubricants and wax lubricants, yarn lubricants which have been found to be especially suitable for purposes of this invention are yarn oil lubricants 3,427,192 Patented Feb. 11, 1969 ICE having a substantially neutral pH such as for instance mineral oil, coconut oil and butyl stearate and combinations thereof.

The film-forming, water-soluble, partial metal salts of styrene-maleic acid copolymers are prepared by alkaline hydrolysis of the corresponding styrene-maleic anhydride copolymer with a metal base or by neutralization to the proper extent of the corresponding styrene-maleic acid copolymer with a metal base. These partial salts are well known in the art. See, e.g., US. Patent 2,490,489. One commercially available form is DM-AS (sodium salt of styrene-maleic anhydride copolymer marketed by Syn- Chem Corporation). To possess the desired film-forming properties, the partial metal salt polymers should have a molecular weight of at least about 2,000, preferably at least about 5,000, e.g., between about 5,000 and about 10,000. As with most such polymers, the molar ratio of styrene to maleic anhydride moieties in the polymer is about 1:1, e.g., from about 0.8:1 to 12:1. Only the partial metal salts are employed in the compositions of this invention, i.e., those polymers containing free carboxylic acid groups, preferably about the mono metal salt. These will have a pH between about 4 and about 9 and preferably about 6.5 to about 8.5 as a 5% aqueous solution. Although any metal salt polymer which is water-soluble can be used, the alkali-metal salts are preferred, especially the monosodium salt.

The film-forming Water-soluble polyurethanes used in the compositions of this invention are also known in the art (see US. Patents 2,948,691, 3,044,898 and 3,061,470). They are prepared by the reaction of a water-soluble polyalkylene ether glycol with about 1 to 1.5 molar equivalents of a diisocyanate with a glycol having sufiicient solubilizing groups so that water-solubility is retained in the resulting polyurethane. Diisocyanates which can be used to prepare the polyurethane include The aryl diisocyanates are preferred. The glycols most frequently used are the water-soluble polyalkylene ether glycols, i.e., the water-soluble polyether glycols which are derived from alkylene oxides or glycols, e.g., those represented by the formula HO(C,,H ,,O) H, in which n is an integer from 2 to 8 and m is an integer from about 15 to about 450. Not all the alkylene radicals present need be the same, as polyether glycols containing a mixture of alkylene radicals can be used. The molecular weights of the polyalkylene ether glycols used to produce the polyurethanes preferably are from about 2,000 to 20,000, more desirably from about 4,000 to 10,000, e.g., 5,500 to 7,000. The term polyalkylene ether glycol includes copolymers of polyethylene ether glycol with polypropylene, polytrimethylene, polytetramethylene, and polybutylene ether glycols. The preferred glycols are polyethylene ether glycols.

The usual polyurethane catalysts can be employed, e.g., bases or organometallic salts, preferably cobalt naphthenate. Materials which promote cross-linking, e.g., polyhydroxy compounds or excessive amounts of water, should be avoided during the reaction to prevent water insolubilization, although small amounts of water appear to impart desirable properties such as improved heat stability. A reaction temperature between about 70 to 95 C. is preferred. A molar proportion of diisocyanate to glycol of about 1.2:1 usually gives the best results. A reaction time which produces a polymer having a viscosity of between 10,000 and 1,000,000 cps. as a 50% solution in toluene at about 80 C. gives good results. These polymers will provide 25% aqueous solutions having a viscosity of about 6,000 cps. or higher at 25 C. These polyurethanes can be further modified by incorporating a lower-alkylene oxide in the terminal portion of the reaction.

The lower-alkylene oxide modification reaction involves the reaction of the polyalkylene ether glycol diisocyanate polymer with an epoxide. This reaction proceeds concomitantly with the primary polymer production, i.e., as soon as some polymer has been produced, it can react with the epoxide. Thus, although the epoxide can be added at almost any point during the primary polymer reaction, the only requirement is that at least the terminal portion of the polymer production is conducted in the presence of the epoxide. The preferred procedure involves adding the epoxide to the reaction mixture a few minutes, e.g., 5 to 30 minutes, before the polymer is chain terminated.

Examples of epoxides which can be employed are the lower-hydrocarbon, i.e., containing from 2 to 12 carbon atoms, epoxides including styrene oxide, a-phenyl propylene oxide, trimethylene oxide, and the lower-alkylene oxides, i.e., epoxides containing from 2 to 8, preferably 2 to 4, carbon atoms, inclusive, e.g., ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide. The epoxides preferably are monofunctional, i.e., contain no other groups reactive to the polymer.

The amount of epoxide which can be added to the polyethylene ether glycol diisocy'anate polymer can be varied over a wide range, i.e., from about 0.1 mole per mole of diisocyanate to the theoretical 2 moles per mole of diisocyanate or more. Conveniently, and preferably if the epoxide is volatile, an excess of the epoxide can be added and the excess removed by distillation or evaporation after the reaction has proceeded to completion.

The epoxide modified portion of the polymerization reaction is ordinarily conducted in substantially the same manner as the preceding portion of the polymerization reaction. However, when a particularly volatile epoxide is employed, e.g., ethylene oxide, it may sometimes be necessary to lower the reaction temperature or employ pressure equipment to prevent excessive loss of the epoxide.

The temperature of the polymerization reaction including the epoxide modified portion, can be varied over a considerable range so long as the reaction is stopped at the desired point. However, the reaction proceeds slowly unless the temperature is above about 70 C. However, the temperature should not exceed 150 C., and preferably should not exceed 110 C. as higher temperatures tend to decompose the polyoxyalkylene chains as well as favor undesirable side reactions. The preferred range is from about 80 C. to 95 C. The reaction time is a function of such factors as temperature, the reactants, catalyst and amount of solvent employed.

The sizing composition employed herein contains a blend of the polyurethane and a film-forming water-soluble partial metal salt of a styrene-maleic acid copolymer. The ratio of copolymer to polyurethane is from about 9 :1 to 1:9 and preferably from about 4:1 to 1:1. The advantages of the copolymer-polyurethane blend and the criticality of the ratios employed are illustrated by the following table which sets forth physical characteristics of cotton/Dacron (polyester fiber produced by E. I. du Pont de Nemours & Co.) warp yarns sized with various compositions.

The copolymer-polyurethane blend, as can be noted from the table, is superior to the standard starch-carboxymethyl cellulose size. The copolymer-polyurethane blend must, however, be blended with a yarn lubricant in order to prevent the size from abrading off and building up at the shuttle. The lubricant may be any compatible lubricant such as for instance higher aliphatic acids, waxes, mineral oils and blown and unblown, drying and semi-drying, vegetable and animal oils and fats.

Higher aliphatic acids which may be employed in this invention are aliphatic carboxylic acids having lubricating properties. These characteristics are typified by the straight chain C to C fatty acids, e.g., lauric, myristic, palmitic, margaric and stearic acid, and u,w-dicarboxylic acids, e.g., azelaic and pimelic acid, and hydroxylated derivatives thereof, e.g., l2-hydroxystearic acid. In practice, these acids are often employed as a mixture, e.g., stearic and palmitic acids and sometimes with substantial amounts of unsaturated acids, e.g., oleic acid.

Waxes which are suitable for use as yarn lubricants in this invention are waxes selected from the group consisting of spermaceti wax, tallow, Japan wax, bees wax, polyether waxes, polyester waxes, paraffin wax and mixtures thereof.

The preferred lubricants are lubricants having a substantially neutral pH such as for instance lubricants which are the esters of olive oil, castor oil, teaseed oil, egg oil, soy bean oil, peanut oil, palm oil, cotton seed oil, neats foot oil and the like. Lubricants which have been found to be especially suitable for purposes of this invention are lubricants selected from the group consisting of mineral oil, coconut oil and butyl stearate and combinations thereof. When the lubricant is applied to the warp yarn subsequent to sizing with the polyurethane-copolymer size, the lubricant should be employed in a manner such that a pickup of from about 0.1% by weight to about 0.6% by weight is obtained based on the dry weight of the unsized warp yarns.

It is preferred that the sizing composition of this invention be applied by means of a two dip application. The size has better adhesion for yarn when the ratio of copolymer to polyurethane approaches equal proportions. The film strength of the copolymer-polyurethane mixture is greatest, however, where the copolymer is employed in amounts which are considerably in excess of the polyurethane. The benefits of the use of a two dip sizing operation are that the first clip will have good adhesion both for the yarn and for subsequent coatings, while the second dip will have high film strength and greater moist air resistance. In general, the first dip should employ copolymer to polyurethane ratios of about 6:4 While the second dip should employ copolymer to polyurethane ratios of from about 3:1 to about 5:1.

Examples of certain specific size bath formulations are given hereinafter. It should be understood, however, that these specific examples are given for purposes of illustration and should not be considered as limiting the spirit or scope of this invention.

FORMULATION A ymer 3.6 Raw coconut oil 0.30 Water 93.7

The formulation is suitable for sizing filament polyester yarns in a single dip operation.

FORMULATION B Percent by weight 5 The formulation is suitable for sizing polyester yarns in a single dip operation.

FORMULATION C Percent by weight Water-soluble polyurethane 3.6 Sodium salt of styrene-maleic anhydride copolymer 5.4 Raw coconut oil 0.54 Water 90.46

The formulation is suitable for sizing polyester yarns in a single dip operation.

FORMULATION D First dip, Second dip, percent by percent by Weight weight Water-soluble polyurethane 2. 7 0. 9 Sodium salt of styrene leic anhydrlde copolymer 2.1 Raw coconut oil 0. 3 N-florannl 0. 10 Water 96. 6

I l u The formulation is especially suitable for SlZlIlg polyester blend yarns in a two dip application.

FORMULATION E First dip, Second dip, 40 percent by percent by weight weight Water-soluble polyurethane 2. 4 0. 75 Sodium salt of styrene-maleic anhydrid copolymer 3. 6 2. 25 N-decano1 0. l0 0. 10 Wax, 1:1 tallow-parafl"1n..- 0. 30 Water 93. 9 96. 6

The formulation is especially suitable for sizing polyester blend yarns in a two dip application.

FORMULATION F First dip, Second dip, percent by percent by weight weight Water-soluble polyurethane 2. 7 Sodium salt of styrene-maleic anhydride copolymer 4. l N-decanol 0. 1O Sodium carboxymethyl cellulose, size grade 3. 5 Sylsize PG (textile formulation marketed by Syn-Chem Corp. containing su1i0- nated tallow and tallow) 0. 35 Water 93. 1 96. 15

The formulation is especially suitable for sizing poly- 3. An aqueous textile sizing composition consisting essentially of water, a yarn lubricant selected from the group consisting of oil lubricants, higher fatty acid lubricants and wax lubricants, a styrene-maleic acid copolymer and a water-soluble polyurethane which is the reaction product of a diisocyanate and a polyalkylene ether glycol, the ratio by weight of the copolymer to the polyurethane being from about 9:1 to 1:9, said lubricant comprising a minor proportion of said polymers 11p to about 10% by weight.

4. The sizing composition of claim 3 wherein said watersol-u-ble polyurethane is an alkylene oxide modified watersoluble polyurethane.

5. An aqueous textile sizing composition consisting essentially of water, a yarn lubricant selected from the group consisting of mineral oil, coconut oil and butyl stearate and combinations thereof, a styrene-maleic acid copolymer and a water-soluble poly-urethane which is the reaction product of a diisocyanate and a polyalkylene ether glycol, the ratio by weight of the copolymer to the polyurethane being from about 9:1 to 1:9, said lubricant comprising between about 5% and 10% by weight of said polymers.

6. The sizing composition of claim 5 wherein said water-soluble polyurethane is an alkylene oxide modified water-soluble polyurethane.

7. An aqueous textile sizing composition consisting essentially of water, a higher fatty acid yarn lubricant selected from the group consisting of lauric, lyris-tic, palmitic, m argaric, stearic, azelaic; pimelic and oleic acids, la styrene-maleic acid copolymer and a water-soluble polyurethane which is the reaction product of a diisocyanate and a polyalkylene ether glycol, the ratio by weight of the copolymer to the polyurethane being from about 9:1 to 1:9, said lubricant comprising a minor proportion of said :polymers up to about 10% by weight.

8. The sizing composition of claim 7 wherein said water-soluble polyurethane is an alkylene oxide modified water-soluble polyurethane.

9. An aqueous textile sizing composition consisting essentially of water, a wax yarn lubricant selected from the group consisting of spermaceti wax, Japan wax, bees wax, polyether wax, polyester wax, paraflin wax and mix- .tures thereof, a styrene-maleic acid copolymer and a water-soluble polyurethane which is the reaction product of a diisocyanate and a polyalkylene ether glycol, the ratio by weight of the copolymer to the polyurethane being from about 9:1 to 1:9, said lubricant comprising a minor proportion of said polymers up to about 10% by weight.

410. The sizing composition of claim 9 wherein said water-soluble polyurethane is an alkylene oxide modified water-soluble polyure thaue.

11. A process for sizing warp yarns comprising coating said yarns with a yarn lubricant, a styrene-maleic acid copolymer and a water-soluble polyurethane which is the reaction product of a diisocyanate and a polyalkylene ether glycol, the ratio by weight of the copolymer to the polyurethane being from about 9:1 to 1:9, said lubricant comprising a minor proportion of said polymers up to about 10% by weight.

12. The process of claim 11 wherein said lubricant is a lubricant selected from the group consisting of oil lubricants, higher fatty acid lubricants and wax lubricants.

13. The process of claim 11 wherein said water-soluble polyurethane is an alkylene oxide modified water-soluble polyurethane.

14. A process for sizing warp yarn comprising first coating said yarns with a styrene-m aleic acid copoly mer and a water-soluble polyurethane which is the reaction product of a diisocyanate and a polyalkylene ether glycol and then superimposing a coating of a yarn lubricant, the ratio by weight of the copolymer to the polyurethane being tfrom about 9: 1 to .1 :9.

15. The process of claim 14 wherein said water-soluble polyurethane is an alkylene oxide modified water-soluble polyurethane.

16. A process for sizing warp yarns comprising subgiecting warp yarns to at least two successive coating operations in aqueous coating compositions comprising a yarn lubricant, a s-tyrene-maleic acid 'copolymer and a water-soluble polyurethane which is the reaction product of a diisocy'anate and a poly-alkylene ether glycol in aqueous medium, the first coating composition employing a copolymer to polyurethane ratio by weight of about 6:4 and the second coating composition employing a copolymer to poly-urethane ratio by weight of from about 3: 1 to about 5 :1.

17. The process of claim 16 wherein said water-soluble polyurethane is an alkylene oxide modified water-soluble polyurethane.

References Cited UNITED STATES PATENTS 2,176,402' 10/ 19159 Koch -1 17-14 3 2,456,283 12/ 1948' Jefferson et a1 252- 89 X Tauch 260-785 Barrett 1-17--139.5 Windemuth et a1. 117-161 Habib 117-1395 Kummerer 117l138.8 Habi'b 1'17- 1'38.8 Barrett 28-7-5 Kum-merer 2'87 5 Kuhn et 211.

WILLIAM D. MAR-TIN, Primary Examiner.

T. G. DAVIS, Assistant Examiner.

US. 01. X.R. 

